Field of the Disclosure
The present disclosure relates to a fluid control device that controls the flow of fluid by using a driver in which vibration is produced, and a pump that includes the fluid control device and sucks and discharges fluid.
Description of the Related Art
Pumps that utilize vibration of a piezoelectric element are commonly used (see, for example, Patent Documents 1 and 2). Such pumps are used for purposes such as directing outside air on a component that has risen in temperature to cool the component, and conveying fluid such as oxygen in a fuel cell.
FIG. 16 schematically illustrates major components of a conventional pump. A conventional pump 101 illustrated in FIG. 16 includes a housing 102, a vibrating plate 103, an opposed plate 104, and a piezoelectric element 105. The vibrating plate 103, the opposed plate 104, and the piezoelectric element 105 are accommodated in the housing 102. The opposed plate 104 defines a pump chamber 110 inside the housing 102. The vibrating plate 103, which is provided inside the pump chamber 110, is positioned facing the opposed plate 104 with a spacing therebetween. The outer peripheral portion of the vibrating plate 103 is elastically supported by the housing 102. The piezoelectric element 105 is stuck on the vibrating plate 103, forming an actuator 111 together with the vibrating plate 103. The housing 102 has, on its upper face, a channel hole 112 that provides communication between the inside and outside of the pump chamber 110. The opposed plate 104 is provided with a channel hole 113 that communicates with the inside of the pump chamber 110. The housing 102 has, on its lower face, channel holes 114 that communicate with the pump chamber 110 through the channel hole 113 and also with the outside.
When voltage is applied to the piezoelectric element 105 of the pump 101, the vibrating plate 103 undergoes flexural vibration in the thickness direction as the piezoelectric element 105 attempts to expand or contract in the in-plane direction. This creates pressure fluctuations in the fluid layer that is sandwiched between the vibrating plate 103 and the opposed plate 104 inside the pump chamber 110, producing a fluid flow such that the fluid is sucked into the pump chamber 110 through the channel holes 114 and 113 and the fluid is discharged to the channel hole 112 from the pump chamber 110.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2013-068215
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2013-053611